ESTROGEN AND INHIBITION OF OXIDATION OF LOW-DENSITY LIPOPROTEINS IN POSTMENOPAUSAL WOMEN

Oxidative modification of low-density lipoprotein (LDL) may be atherog enic. We studied the time of onset of LDL oxidation (lag) in 18 postme nopausal women before and after intraarterial infusion of 17beta-oestr adiol, after 3 weeks' patch administration ir 12 of these women, and 1 . month after discontinuation in 10. The lag increased from baseline a fter acute infusion (from 134 [SD 41] to 167 [36] min, p = 0.01) and a fter the patch (132 [31] to 178 [45] min, p = 0.009). After discontinu ation of oestradiol, the lag returned to baseline. This study shows an antioxidant effect of physiological levels of 17beta-oestradiol, whic h may contribute to an anti-atherogenic action.